1. Field of the Invention
This invention relates to wearing apparel and more particularly to a suit of protective clothing having temperature controlled air under positive pressure in a diffuser area of the suit.
2. Description of the Related Art
Persons who work with toxic or noxious chemicals or in areas contaminated with airborne hazardous substances, such as farmers applying pesticides or cleanup or other workers in polluted environments must wear protective, nonpermeable, outer clothing that substantially encloses their bodies to shield them from these chemicals. These protective garments, whether nonporous or of limited porosity may become very warm under the working conditions, which are often in high temperature areas. Where the hazards are most severe and the required clothing must be very protective, workers may be unable to work at full efficiency for more than a short time without leaving the working area to cool off or without suffering heat-related health problems. Agricultural workers engaged in pesticide application or in handling other chemicals must generally remain in large, expensive protective and air-conditioned, air-filtered tractor cabs to be protected from chemicals if they are not to be overcome by the heat generated during working in a protective suit.
A variety of cooling garments and associated cooling systems have been developed in an attempt to solve this problem. One means that has been developed to cool a worker's body utilizes cooling packs or strips that are attached to or incorporated within a garment. The cooling packs add bulk to the garment and require pre-cooling of the packs and periodic changing of the packs but they do allow the garment to be portable.
Many other cooling systems are not portable and require long lengths of insulated hose between the cooling unit and the worker, particularly if the worker's job requires extensive mobility. Wherever the cooling mechanism relies on lengths of hose to carry the cooled air to the worker, the air in the hose may heat prior to reaching the person unless there is additional cumbersome, expensive insulation. Many portable units are also cumbersome and bulky for the worker to carry. In some cases, the cooling system may be attached to a mobile compressor. Thus, protective garmets have been attached to motorized vehicles to provide heated air from the heat of the engine (U.S. Pat. No. 4,146,933). The disclosure of this patent and all other cited patents is hereby incorporated herein by reference.
Other workers may need protective suits in severely cold weather and require a means of keeping both warm and free of hazardous substances.
Vortex tubes are used in a wide variety of cooling systems including protective clothing. They are generally lighter than a portable air conditioning unit, less expensive, and easier to regulate. In a vortex tube, high pressure air enters the inlet, and goes through a vortex generation chamber and into the hot-tube portion of the vortex tube. Under centrifugal force, the air spirals down the inside of the tube, going around the inside of the walls toward the hot end where some of the air escapes. The remaining air returns up the center of the tube, through the vortex generation chamber and out the cold outlet. A control valve at the hot end allows variation of the fraction of air that is cold and thus the coldness of the cold outlet.
Although vortex tubes have often caused problems by creating excess hot or cold air or excess noise, these problems have been overcome in currently marketed vortex tubes and associated protective mufflers and insulative materials. The temperature of air emitted from vortex tubes may be regulated in a variety of ways, for example by means of movable flow-dividing members as discussed in the patent of Inglis (U.S. Pat. No. 4,240,261), by means of a plurality of vortex tubes as in Shackson (U.S. Pat. No. 3,103,104) or by valves and a thermostat as in Green (U.S. Pat. No. 2.819.590).
Most temperature-regulated protective garments, including those utilizing vortex tubes, utilize some type of conduit for conducting the cooled or heated air to various places around the wearer's body. In the individual cooling unit of Hayashi (U.S. Pat. No. 3,630,039), air from a compressor goes through a pipe placed in a cooling tank for precooling and then to a vortex tube mounted on the person. Distributor pipes of unspecified construction are connected to the cold-air outlet of the vortex tube for diffusing air into the interior of the worker's clothes. In Messick's air cooling unit (U.S. Pat. No. 3,291,126), a vortex tube is connected to the air source. Cooled air is conducted by conduits from the vortex tube cooling end to the hand and leg areas. The conduits are closed on the ends and have outlet slots or slits along their sides for air release.
An air-conditioned vest that connects to a vortex tube but does not use inner garment conduits is sold by Vortec Corporation (Cincinnati, Ohio). This vest is generally worn under protective coveralls or suits. Air enters the double layer vest from a waist worn vortex tube and escapes from holes positioned in selected areas of the vest's lining over the wearer's clothing worn under the vest. The neck area is cooled by air from a separate hose that runs to a neck ring or a helmet.
Vortex tubes have also been used for heating garments, such as in the diving suit heater of Marcus (U.S. Pat. No. 3,815,573). Heated gas from the vortex tube is passed through a fluid-filled heat exchanger and the heated fluid is pumped through channels in a diving suit.
Garments not utilizing vortex tubes but relying on conduits to convey temperature-regulated air include those of Melander and Moretti. Melander's wearable ventilation system (U.S. Pat. No. 4,194,247), is worn under an outer protective garment. A manifold receives ventilating gas and supplies the gas to one or more manifold outlets that are each connected to flexible fabric gas distribution conduits having pin-size orifices. A head distribution tube may have enlarged orifices near the face area.
The ventilated system of Moretti (U.S. Pat. No. 4,271,833) includes a head enclosure and body suit of either permeable or impermeable material. Pressurized air is provided to each limb of the wearer and respiration air is provided to the head enclosure by means of a manifold having multiple air outlets. The manifold is strapped to the user's trunk and is connected to an air source. Air flow from the air source is regulated by the manifold as it flows through conduits to be released into diffuser means on each limb of the user. The diffusers each are made of two layers, one of which is non porous and the other of which is microporous material. Air goes through the pores and spreads over the wearer's limbs.
Temperature-regulated air from non-vortex tube sources may also be fed directly into garment areas on the person's arms, legs and head as in Jenkins. The conditioned-air suit of Jenkins (U.S. Pat. No. 4,146,933) has multiple places for connection of air-conditioning hose connections. Air from either an unspecified cold air source or a hot air source such as an engine is placed in the garment between the garment and the wearer's inner clothing down the arms and legs and into a lined hood area to insulate the wearer from ambient conditions. The air pressure causes some leakage of the air from the garment.
To keep toxic substances from entering a garment and to keep them away from the wearer's head, pressurized air may also be made to flow into the interior of a garment and out over the face area. The two-layered vest of Kristensson (U.S. Pat. No 4,558,466) has a lower area where both layers are impermeable and an upper area where the outer layer is air-permeable. Fresh air at an agreeable ambient temperature is introduced into the lower inner portion of the vest and flows upward and outward from the area between the vest layers. Kristensson does not utilize a vortex tube nor any other particular source of cooled or heated air.
Other ventilated garments that do not include attached gas sources may utilize flaps over air permeable fabrics or perforated panels and other ventilation openings (for example, U.S. Pat. Nos. 4,513,451, and 4,608,715). These garments do not provide continuous, regulated or evenly distributed ventilation nor is there reliable positive air pressure within the garment to keep out toxic substances.
Many protective suits require extensive cleaning efforts to make them reusable once they are contaminated. Cleaning of garments having complicated conduits for air may result in damage to or clogging of the conduits. The cost of many of these garments is often too great to make it cost effective to treat them as disposable. As cost decreases, the likelihood of the protective garments having effective temperature regulation systems also decreases, particularly since expensive conduits and other components of the temperature-regulation system may be built into the garment itself.
It is therefore an object of this invention to provide temperature-regulated protective garment that utilizes a vortex tube.
It is a further object of this invention to provide a type of temperature-regulated protective garment that may be used in chemically hazardous areas, including agricultural and industrial environments.
It is a further object of this invention to provide a type of temperature-regulated protective garment that improves worker efficiency and increases the amount of time a worker may work per day.
It is a further object of this invention to provide a type of temperature-regulated protective garment that is inexpensive enough to be used as a disposable garment in a cost effective manner but is designed to withstand repeated use and exposure to chemicals.
It is a further object of this invention to provide a temperature-regulated protective garment in which the more expensive components of the temperature regulation system are detachable from the garment.
It is a further object of this invention to provide a temperature-regulated protective garment that does not have complicated conduits or other internal flow mechanisms that are easily clogged or damaged in use or cleaning.
A further object of this invention is to provide a temperature-regulated protective garment that is close to the air temperature regulator.
A further object of this invention is to provide a temperature-regulated protective garment that may be attached to a variety of air sources, including a tractor-attached compressor.
Other objects and advantages will be more fully apparent from the following disclosure and appended claims.